算法提高 5-3日历

#include <stdio.h>

int daynum[13] = {0,31,28,31,30,31,30,31,31,30,31,30,31}; //二月暂以平年记 

int IsLeap(int year){
    if((year%4 == 0 && year%100 != 0) || year%400 == 0)
        return 1;
    return 0;
}

int WeekDay(int year,int month){
    int daycount = 1; //某月第一天 
    int i;
    for(i=2007;i<year;i++){
        daycount += (IsLeap(i) + 365); // great;
    }
    for(i=1;i<month;i++){
        daycount += daynum[i];
    }
    if(month > 2)
        daycount += IsLeap(year);
    return daycount%7;
}

void Print_Calendar(int year,int month,int day){
    int i,count;
    printf("Calendar %d - %02d\n",year,month);//%02d
    printf("---------------------\n");
    printf("Su Mo Tu We Th Fr Sa\n");
    printf("---------------------\n");
    for(i=0;i<day;i++)//输出第一行数字前的空格 
        printf("   "); //三个空格
    for(i=1;i< (7-day);i++) 
        printf("%2d ",i);
    printf("%2d\n",7-day);//最后一个数字不带空格 
    if(month == 2 && IsLeap(year))
        daynum[month] += 1;
    count = 0;
    for(i=7-day+1;i<=daynum[month];i++){
        count ++;
        if(count % 7 == 0)
            printf("%2d\n",i);
        else{
            if(count == daynum[month]+day-7) //最后一行特别处理 
                printf("%2d\n");
            else{
                printf("%2d ",i);
            }
        }
    }
    printf("---------------------\n");
}

int main(){
    int year,month,day;
    scanf("%d%d",&year,&month);
    day = WeekDay(year,month);
    Print_Calendar(year,month,day);
    return 0; 
}